In what may be one of the fastest deployment projects, the ISA 100.11a Wireless Compliance Institute (WCI) has completed an installation of a fully operational wireless instrumentation network following the new standard at the Arkema organic peroxide plant in Crosby, TX.

This project is already operating, even though the ISA100.11a Process Automation Applications Wireless Standard was ratified less than a month ago. It involves a group of specific monitoring points in the plant that were either inadequately instrumented or where the company wants to expand coverage. According to WCI, the devices are deployed in several areas:

• 500,000 gal. firewater tank: Wireless level sensor ensures firewater tank is full at all times;• Cold storage: Wireless temperature and door sensors provide central reporting of exception conditions at cold storage warehouses;• Wastewater tank: There is a wired level sensor on a wastewater tank that feeds its values into a satellite control room close to the tank, but not the central control room. To provide central visibility to this information, an ISA100.11a adaptor sends the data to the central control room; and• Gas sensor: A single wireless SO2 sensor was installed alongside an existing wired sensor. Following successful pilot, wireless gas sensing can be expanded.

Honeywell 11a transmitter

In many respects, the specific applications of the devices are not as important as what the project demonstrates. WCI is trying to prove is that ISA 100.11a can be a multi-vendor platform with full interoperability. The devices in this case are made by Honeywell, Yokogawa, and Gastronics, with the wireless infrastructure provided by Honeywell and Nivis. WCI members make the point that while these individual devices were essentially hand made, the communication stacks and testing tools were already complete before the final ratification, so the transmitters were tested and are fully compliant with the standard.

Companies participating in the demonstration wanted to make sure that the system showed all the critical operational elements, including device level meshing. 11a is designed to be a one-hop topology, although devices can send signals through the mesh if a direct connection with the gateway is not possible at any given time. Working with Arkema, the participants had to create a barrier using some strategically placed steel shipping containers, but the system responded as expected and routed the transmission around the impediment.

Honeywell and Nivis gateways

At present, the wireless devices feed into a separate monitoring point, but Arkema expects to integrate them fully into its main control architecture as well as adding more devices as they become available.